Redox substoichiometry in neutron activation analysis. Determination of antimony in metallic tin.

Redox substoichiometry in neutron activation analysis has been applied to the determination of antimony content in metallic tin of chemical grade. The substoichiometric separation is based on the extraction of unreacted antimony(III) with an excess of N-benzoyl-N-phenylhydroxylamine (BPHA) after the substoichiometric oxidation of antimony(III) with potassium bromate, such as arsenic(III), could be prevented by the addition of large amounts of antimony(III) carrier before substoichiometric oxidation. Only about one hour is required for the antimony analysis of metallic tin, excluding the irradiation period of sample. The antimony content of 1.22 +/- 0.14 microgram tin (10 mg) was determined without separation of the matrix element.